Pneumatic tool



(NdMoaeLj J. G. CARLINET.

PNEUMATIG TOOL.

JOHN G. OARLINET, OF PHILADELPHIA, PENNSYLVANIA.

PN EUNATIC TOOL.

SPECIFIGATION forming part of Letters Patent No. 534,812, dated February26, 1895. Application led October 24,1894. Serial No. 526,829. (Nomodel.)

To ctZZ whom it may concern.'

Be it known that I, JOHN G. CARLINET, a citizen of the United States,residing at Philadelphia, Pennsylvania, have invented certainImprovements in Pneumatic Tools, of which the following is aspecification. i

The object of my invention is to construct a pneumatic tool in such amanner that the jar and trembling caused by the striking of the toolupon the article to be cut will be to a great extent lessened.

In pneumatic tools as ordinarily constructed, owing to the number ofstrokes given in rapid succession the operator is prevented from workingcontinuously with the tool as the strain upon the nerves is very greatowing to the fact that the operator takes the back thrust of the toolwhen the plunger is driven forward.

In the accompanying drawings:-Figure l, is a longitudinal sectional viewof my improved pneumatic tool with the outer plunger in action. Fig. 2,'is a similar view with the central 4plunger inaction. Fig. 3, is a`transverse section on the line 3 3, Fig. l. Fig. Lhis a transversesection on theline4-4., Fig. 2. Fig. 5, is a transverse section on theline 5-5, F-ig. 1.

A tool made in accordance with my invention operates in the same manneras if the two pistons were arranged in two chambers in the casing andthecompressed duid acting upon them independently, one plunger returningwhile the other is moved forward. Thus the returning piston takes up thejar or trembling caused by the acting piston striking the blow. Y

Referring to the accompanying drawings, A is the casing made up of threeparts, the cylinder a, and the heads ct', a2, screwed into the cylinder,as shown in the drawings. The heads may be fastened in any mannerdesired withoutdepartingfrom myinvention. Adapted to' the head a2 is ananvil B carrying the tool c and having an annular head b and a centralhead b projecting' beyond the annular head.

D is an annular piston fitting snugly within the casing A and adapted toreciprocate between the head a. and the annular head b of the anvil. dCZ are the fluid chambers one atl each end of the piston in the casing.

Within the cylindrical piston D is a central piston E also adapted toslide in the head d as well as in the annular piston. This piston Ereciprocates between the head b of the anvil B and the shoulder 0,3 ofthe head a. ce are fluid chambers one at each end of the central pistonE, so vthat it will be seen that the pistons D and E each Ahaveindependent iiuid chambers. It', for instance, the fluid enters thespace CZ in front of the annular piston D it will force the piston Dback, but will not act upon the piston F.. The fluid in the chambere atthe back of the piston E will force the said piston toward the anvil atthe same time that the fluid acts upon the piston D so that in all casesthe casing itself intervenes between the two pistons.

I preferably make the passages for the ingress and escape of fluid inthe manner shown in the drawings. l

The inlet passage a4 in the head a for the Huid under pressure,preferably compressed air, communicates with the passage c2 extendingpart way into the piston E and this passage communicates with transversepassages @3 and c4; the passages e3 communicating directly with thechambers c at the back of the piston E when the piston is in theposition shown in Fig. l, and the passages e4 communicating with thechambers CZ back of the piston D when the piston E is in the positionchamber c in front of the piston E exhausts through the passage i in thepiston E into the annular chamber h in the head c. and through theexhaust h; while the air from the chamber d exhausts th rough thepassage t" into the ICO chamber d through the passages g and g,f,

1o f and f2 and exhaust chamber h. Thus by this arrangement of the portsand passages rapid movement is imparted to both pistons in oppositedirections.

I preferably arrange between the anvil and the head a2 of the casing aseries of washers m and a coiled spring on in order to form a yieldingabutment for the anvil.

It Will be understood that two or more pistons maybe arranged side byside in some instances instead of concentric, as shown in the drawingswithout departing from the main feature of my invention.

I claim as my invention- 1. The combination in a pneumatic tool of thetwo pistons both mounted in the casing and independent of each other andoperating in opposite directions, with independent Huid chambers for thepistons, and valve mechanism by which fluid under pressure is admittedto the forward end of one piston and to the rear end ot the other pistonsimultaneously, substantially as described.

2. The combination in a pneumatic tool of the casing, the anvil, theconcentric plungers, independent chambers at eachv end of each plunger,valve mechanism through which .fluid under pressure is admitted to theforward end of one piston andthe rear end of the other pistonsimultaneously so that the pistons will move in opposite directions,substantially as t described.

3. The combination in a pneumatic tool, of the casing, the heads a', a2,the anvil having heads b b, the annular piston D and the central pistonE, with inlet and exhaust ports arranged substantially as described, sothat uid under pressure will be admitted in front of one pistonsimultaneously with the admission of fluid at the rear of the otherpiston, substantially as described.

4. The combination in a pneumatic tool, of the casing, the anvil havingthe annular head h and the central head b', the annular piston D and thecentral piston E, inlet and exhaust passages in the piston E,apassageinthe piston D, said passages being so arranged that fluid under pressurewill be admitted to the forward end of one piston and at the rear end ofthe other piston simultaneously, substantially as described.

5. The combination in a pneumatic tool, of the' casing, the anvil havingthe two heads, the annular piston D and a central piston E, inletvpassage for the [luid under pressure in the casing, the passage e2 inthe central piston, transverse passages c3 c4 communicating alternatelywith the chambers e and CZ in the casing and a passage f forming acommunication between the chambers e and the annularchamber f', apassage g in the piston D communicating with the chamber f and with thechamber d in front of the piston D, an exhaust chamber h in the casing,the passaget' in the piston E extending from the chamber in front ofsaid piston and communicating alternately with the chamber d and exhaustchamber h, substantially as shown and described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN G. CARLINET.

Witnesses:

WILL. A. BARR, JOSEPH H. KLEIN.

